1. Field of the Invention
The present invention relates to a heating installation for premises or residential or industrial use.
2. Description of the Prior Art
For a long time, attempts have been made to heat and/or cool premises for dwelling or industrial use, by using techniques achieving a performance coefficient as high as possible, in order to reduce the consumption of primary energy and more particularly petroleum products from which fuels for domestic use are extracted. More and more research is being undertaken to use new energy forms and/or to reactivate energy forms which can be applied in techniques with a high performance coefficient.
Thus, heating installations utilizing a heat pump are becoming of notably increased interest. This is because the heat pump is an apparatus capable of transferring heat which is unusable directly and taken from a low temperature source of heat, to another medium where the heat is then at a sufficient temperature to be useful under certain conditions.
Among heating installations using the heat pump, are those which are based on a water-water, ground-water, water-air or ground-air exchange. By utilizing special mixtures of cold generating fluids such as fluorinated hydrocarbons, it is possible to increase the temperatures of the heating fluid by several tens of degrees. However, this type of installation necessitates large water sources such as lakes, ground water sheets or an adequate terrain in the case of a ground-water heat pump.
To escape from the necessity for the availability of a large source of water or of a suitable terrain, a heat pump based on air-water or air-air exchange has been used.
To take advantage of the cold source constituted by the outer air and to use it at less negative temperatures, it has been proposed to reheat this air by an independent heating source to bring it to the temperature of use, namely above 0.degree. C. This technique, attractive as it appears, does not entirely give satisfaction since it must be adapted to the external climatic conditions. Moreover, it necessitates the use of an independent heat source and hence the use of additional energy to that supplied to the heating installation. This is irrelevant for the majority of heat pumps using the outer air as a source of cold. In fact, the performance coefficient of the heat pump is all the better as the outer temperature is higher while the energy needs of the site to be heated diminish.
To avoid installations prohibitive, as to price and bulk, manufacturers propose mixed systems where the heat pump may be relayed or completed at low external temperatures by conventional supplementary heating such as a burner or an electrical resistor. The economic point of equilibrium for which the heat pump is just adapted in power to the premises to be heated is generally located between -2.degree. C. and +6.degree. C. For equilibrium points higher than +6.degree. C., the annual performance coefficient is degraded by the poor performance coefficient of conventional supplementary heating. For equilibrium points below -2.degree. C., the dimensions of the heat pump become unacceptable and approximate those of an evaporator.
Finally, it is to be noted that heat pumps using water as a hot source, are not adaptable to existing heating installations without supplementary heating. As for new heating installations, they necessitate higher investments by reason of the greater dimensions of the heating surfaces due to the fact of the technical and economic limitations relating to the temperature of the hot water.
It is an object of the present invention to overcome the foregoing drawbacks and to provide a heating installation which does not reply upon any supplementary heating, and which can operate over large temperature ranges, with a reduced bulk.